Today the number of cylinders in a car engine is pretty much defined by the type of car it is in. Economy cars tend to have 4-cylinder engines, mid-level sedans have six, trucks have eight cylinders and exotic sports cars have 12. That’s it right? Well, today it is but go back in time 80-90 years and there were several 16-cylinder cars. And they weren’t around for long.
The roaring 20s
Back in the 1920s, the standard engine in virtually all cars was an in-line four. When more power was needed, automotive engineers just made them bigger and higher compression. The problem was that just making pistons bigger introduced vibration problems and increasing compression ratios introduced pre-ignition problems (Note: www.bobfisherchev.com reminds us that this was way before leaded gas was available.) The solution? Add more cylinders. Adding more cylinders not only gave you more displacement, the additional moving masses smoothed out engine vibrations.
Cadillac jumps in
Since all the major manufacturers were running into the same problem, quite a few started to work on V-12 engines. Cadillac was one of them, but behind the scenes they were also working on their first V-16. Their V-16 design was essentially two straight-eight engines cast together which shared a common crankshaft. Its bore and stroke were just 3 inches and 4 inches. The overall displacement was 452 cubic inches making it one of the biggest car engines of the time. And unlike conventional flathead V-8 engines, the Cadillac V-16 had overhead valves and hydraulic valve lifters making it one of the smoothest, quietest engines ever built. The only problem was that they were very expensive to manufacture and Cadillac ceased production in 1939.
British Racing Motors
Although their application wasn’t for passenger cars, British Racing Motors (BRM) designed a high-performance V-16 engine in 1947. It was designed primarily for Formula One motor racing and it was hot. Accord to the factory, the BRM V16 put out some 600HP and could easily spin up to 12,000 RPM. The problem with the BRM was reliability. It was a very complex engine and possessed such poor reliability that it was unusual for a BRM V16 to finish most races.
almost 500hp thanks to its supercharger. But its power delivery was so peaky, Stirling Moss described it as the worst car he’d ever driven. Which was when it was running, which wasn’t often because the engine was so far ahead of its time, the metallurgy didn’t actually exist to allow it to function properly. It took BRM four years to get it working properly, by which stage the car it was in was obsolete.
The Porsche Flat-16
Built in the late 1960s, Porsche made a flat-16 that was built just for racing purposes. It was going to be the motor that powered Porsche’s 917s that would compete in the no-restrictions Can Am series. Power was big back in those late ‘60s/early ‘70s days, and Porsche’s first thought at making more power than their flat 12 was to build up to a 16. Just a few were build before Porsche moved on to other projects.
Still made today
Yes, you can still get a car with 16-cylinder engine in it today. The only problem is that the car will cost you almost 3 million dollars. This car is the ultra-exotic Bugatti Chiron and it comes loaded with their impossibly complex W16 engine. The W16 designation is used because it’s made up of two narrow-angle V8s, which forms a ‘W’. The vee in the V8s is so narrow (15 degrees) that a pair of camshafts can open and shut all 32 valves for each bank of eight cylinders, unlike in most overhead-cam V8s, which have quad camshafts.
The W16 comes with a pair of turbochargers per cylinder bank (for a total of four turbos) and is capable of over more than 1000hp. Bugatti has the title of world’s fastest car firmly in the crosshairs and will likely meet those expectations.